Info Needed For Custom Burn Settings And Max DVD Length?

[Ian R. Brown]

I would like to use the Custom Burn Settings but know little about them. The Help Manual gives little information other than trying to warn me off!

 

Whenever I open the Custom Settings, the Average Bitrate is 4 and the Maximum is 8 although both can be set to 9.

 

Is there anywhere on the internet where I could get a reasonably simple explanation of these controls and the ramifications of their use?

 

Also I can find no details of maximum lengths for DVDs. On my Philips DVD Recorder I can record 1, 2 3 4 or 6 hour DVDs (at different qualities of course).

 

In iDVD 4 I can use either the "Best Performance" setting which allows an hour or "Best Quality" that enables up to 2 hours of recording.

 

In an effort to determine Toast's Maximum DVD length I put in 5h.58m. of video and Toast was quite happy to open my DVD tray when I pressed "Burn".

 

Needless to say I aborted it - but there were no warnings that I had too much material.

 

So is there a maximum time limit?

 

Ian.

[tsantee]

That's a difficult question to answer. A fair guide to how much will fit the disc is the green bar that surrounds the burn button. Because Toast does variable bit encoding the amount of space required actually depends on the content of the video itself. If there is lots of action and changes in the scene then the encoding requires more space and if you have a video of watching the sun set then it takes much less space.

 

There's a Mac applicaiton called MrBitbudget that provides some calculations for the average bit rate that will fit on a DVD. I don't know if it is still available.

 

Your Philips DVD recorder reduces the resolution as well as the bit rate for longer recordings - probably at 3 hours or more. Toast does not reduce the resolution below the 720 x 480 (if you are using NTSC) so it typically can fit up to about 3 hours of video on a single-layer disc when using the Automatic setting. You might get more if you lower the average and maximum bit rates significantly.

 

Audio also is a factor. PCM audio is uncompressed so the maximum video you'll fit to a disc with PCM audio is about 90 minutes. Choosing AC-3 audio, therefore, is important. A lower setting for AC-3 audio will increase the space available for video.

 

What I do when I'm uncertain about the right setting is choose Save as Disc Image instead of clicking the burn button. Toast encodes to fit up to a dual-layer DVD. If the result is too large for a single layer disc I can choose the disc image in the Copy window and Toast's Fit-to-DVD will do additional compression to maximally fit a single-layer disc.

 

The default setting in Toast is very good quality, but the way. If you have a shorter than 2 hour video you can raise the average setting, but I wouldn't increase the maximum setting. Also, turning on Half-Pel can increase picture quality.

[Ian R. Brown]

Thanks tsantee.

 

Actually I am using PAL (UK).

 

Normally I would not want a long DVD - certainly no more than an hour or so - I am simply curious.

 

Actually, now I come to think about it, I have used Toast to copy a dual-layer DVD that lasted 4 hours (onto a single layer DVD-R). So presumably there would be no problem with making a 4 hour video in Final Cut and burning it - not that I would actually do such a thing.

 

With regard to using Custom Settings, I suspect that by fiddling around and tweaking everything to perfection, the improvement would probably be so slight as to be imperceptible.

 

Still it would be nice to know exactly how to set the parameters for different subjects.

 

Ian.

[tsantee]

Thanks tsantee.

 

Actually I am using PAL (UK).

 

Normally I would not want a long DVD - certainly no more than an hour or so - I am simply curious.

 

Actually, now I come to think about it, I have used Toast to copy a dual-layer DVD that lasted 4 hours (onto a single layer DVD-R). So presumably there would be no problem with making a 4 hour video in Final Cut and burning it - not that I would actually do such a thing.

 

With regard to using Custom Settings, I suspect that by fiddling around and tweaking everything to perfection, the improvement would probably be so slight as to be imperceptible.

 

Still it would be nice to know exactly how to set the parameters for different subjects.

 

Ian.

Since you aren't looking to fit long videos to DVD, keep the upper slider at 6 mbps or better. You might not see little difference between 6 mbps and 8 mbps, but you should see a difference between 4 and 6.

 

With the audio at 256 kbps, here's an approximate breakdown of average video bit rates to fit a single-layer DVD:

 

8 mbps: up to 73 minutes

7 mbps: up to 82 minutes

6 mbps: up to 95 minutes

5 mbps: up to 114 minutes

4 mbps: up to 140 minutes

3 mbps: up to 180 minutes

[Ian R. Brown]

Thanks for those further details. Can I ignore the Maximum Bit Rate setting or should that always be higher than the average one?

 

Incidentally I found MrBitRate on Version Tracker but whenever I pressed "Download" I got through to a site called Planmil !

 

Ian.

[tsantee]

Thanks for those further details. Can I ignore the Maximum Bit Rate setting or should that always be higher than the average one?

 

Incidentally I found MrBitRate on Version Tracker but whenever I pressed "Download" I got through to a site called Planmil !

 

Ian.

I'd just leave the maximum bit rate where it is unless you were trying to squeeze more video on a disc. In that case I'd lower it, but keep it at least at 5 (with the average less that 5).

 

MrBitbudget was freeware so if you want it send me a private message and I'll put it on my iDisk. It is ungraceful when quitting as it always causes the OS to present the unexpected quit dialog box.